1. Field of the Invention
The present invention relates to an image reading apparatus and an image reading method for reading an image of an original sheet, and to an image forming apparatus and an image forming method for forming an image of an original sheet on a predetermined object.
2. Description of Related Art
According to an earlier development, in case that a plurality of original sheets having different sizes are mixed, as a method for reading each image described on a plurality of original sheets once, the following method was used. The method will be explained with reference to FIG. 5.
FIG. 5 shows a timing chart for explaining an operation of an original sheet mixing mode according to an earlier development. The original sheet mixing mode is selected and designated with a control panel 201 of the image forming apparatus. The designating signal is transmitted to a condition control section 210. Further, the designating signal is transmitted from the condition control section 210 to an image processing section 220 (#501) and to an automatic document feeding device 100 (#502). The automatic document feeding device 100 notifies the condition control section 210 of a response that the operation of the automatic document feeding device 100 is started (#503).
After receiving the signal #502, the automatic document feeding device 100 feeds the uppermost original sheet P (#504). Even though the original sheet P reaches the position shown in FIG. 4, a reading operation is not started. The original sheet P is fed until the original sheet P reaches the position shown in FIG. 2. When the original sheet P reaches the position shown in FIG. 2, as described above, the size of the original sheet is detected by the original sheet size detecting section 107. Then, the automatic document feeding device 100 notifies the condition control section 210 of the size of the original sheet P (#505). The condition control section 210 notifies the image processing section 220 of a compressed size (#506).
Next, the automatic document feeding device 100 switchbacks the original document P so that the front end of the original sheet P is returned slightly behind the read sensor 115 as shown in FIG. 6 (#507). Then, the original sheet P is forwarded again. When the original sheet P reaches the position shown in FIG. 4, the reading of the image of the original sheet is started (#508). At the same time, an image reading signal is transmitted to the image processing section 220 (#509). The page memory 222 carries out an image compressing operation (#510). When the image reading operation finishing signal is transmitted (#511), the finishing signal is outputted to the condition control section 210 (#512). In the automatic document feeding device 100, continuously, the original sheet discharging operation is started (#513). When the discharging operation for the original sheet is finished, a signal for stopping the operation because of the finish of the discharge, is outputted to the condition control section 210 (#514). As described above, according to an earlier development, because the original sheet returning operation is required, there was a problem that the efficiency of the image forming apparatus in the original sheet mixing mode is extremely lowered.
In order to solve the above-described problems, an object of the present invention is to provide an image reading apparatus, an image forming apparatus, an image reading method and an image forming method, which can start to read an original sheet without carrying out the switchback of the original sheet to recognize the size thereof, even though the original sheet has any size.
That is, in accordance with the first aspect of the present invention, an image reading apparatus comprises:
a detecting section for detecting a size of an original sheet;
an image reading section for reading an image described in the original sheet; and
a storage medium for storing the read image which is read by the image reading section;
wherein before the size of the original sheet is detected by the detecting section, the image reading section reads the image to store the read image in the storage medium; and
after the size of the original sheet is detected by the detecting section, a size of the stored image which is stored in the storage medium is changed in accordance with the detected size of the original sheet, which is detected by the detecting section.
The image reading apparatus may further comprise: an automatic document feeding device for automatically feeding the original sheet from the detecting section to the image reading section. The detecting section is provided in the automatic document feeding device and the detecting section may detect the size of the original sheet by passing a front end of the original sheet and a rear end of the original sheet through the detecting section.
In accordance with the second aspect of the present invention, an image forming apparatus comprises:
the above-described image reading apparatus; and
an image forming section for forming the stored image having the changed size.
The phase xe2x80x9cform an imagexe2x80x9d includes the meaning that the image is printed on a medium, such as a paper, a cloth, a plastic or the like, and the meaning that the image is projected a display, such as a CRT, a TFT or the like, or a screen or the like.
Before the size of the original sheet is detected by the detecting section, the storage medium may store the read image assuming that the size of the original sheet is a maximum original sheet size which is allowable for the image forming apparatus.
The image forming apparatus may further comprise: a copy sheet automatic selecting device for automatically selecting a copy sheet in accordance with the size of the original sheet and a reduction or enlargement magnification.
The image reading apparatus is one for reading the image, however, is one which is not required to form the read image. For example, a facsimile, a scanner and the like are exemplified.
The image forming apparatus is one for forming the read image. For example, a copier machine, a printing machine (a printer), a projector and the like are exemplified.
In accordance with the third aspect of the present invention, an image reading method, comprises:
detecting a size of an original sheet;
reading an image described in the original sheet; and
storing the read image;
wherein before the size of the original sheet is detected, the image is read to store the read image; and
after the size of the original sheet is detected, a size of the stored image is changed in accordance with the detected size of the original sheet.
The image reading method may further comprise:
automatically feeding the original sheet;
wherein the size of the original sheet is detected by passing a front end of the original sheet and a rear end of the original sheet through a detecting section.
In accordance with the fourth aspect of the present invention, an image forming method, comprises:
the above-described image reading method; and
forming the stored image having the changed size.
Before the size of the original sheet is detected, the read image may be stored assuming that the size of the original sheet is an allowable maximum original sheet size.
The image forming method may further comprise:
automatically selecting a copy sheet in accordance with the size of the original sheet and a reduction or enlargement magnification.